[banjojo]

Please bear with me as I attempt to describe our issue:

We live in a quad level home that has two identical TempStar LP furnaces (F9MVE0401410A3), one in the basement and one in the crawlspace. These were self-installed last November by my husband and father who are not HVAC guys but both are very mechanically inclined. The unit located in the basement has never had an issue. However, the unit in the crawlspace has been throwing error codes (I believe it's 6 flashes) from the very beginning. It generally will run flawlessly on mild days but once the temperature drops, it continuously shuts down and the ignition locks out over and over. We've cleaned the flame sensor, insulated and wrapped the condensate line with heat tape, adjusted the gas pressure, and probably done several other things that I'm forgetting right now. Has anybody dealt with anything like this? We're in a rural area and are having a hard time getting somebody to come out. The guy we purchased it off of came out once, but the furnace never failed while he was here so he claimed it was working fine.

 

[user_12345a]

Should have flame sensor current measured (DC micro-amps) and make sure the furnace has a good ground.

this is assuming the first code is failure to detect flame.

 

[viper]

Not sure I understand how the problem manifests. Does it shut down after a minute or two? 10min? Does it try to relight? It sounds like a flame sensor issue BUT, you may want to read my own thread I posted here last night. It was puzzling and at least now I know.

The reason I mention is because a gas valve doesn't have a feedback loop to sell any controller it is certainly working, that I am aware of. maybe some sense the amperage to the coil (which should be a thing) which would certainly get flagged but without that, all a control sees is "I commanded the gas valve to turn on".

A subsequent "flame out" condition could either be the gas valve shutting down or the flame sensor causing the controller to shut the gas valve down.

Seasoned pros -- You guys know if this controller would be looked at the current to the gas valve as verification of good operating status?

Also you mention cleaning the flame sensor. Due to the time and cost, you might consider just replacing it if you don't have the tools or knowledge to test it. You can bench test those with a torch and meter.

And I don't know how you sneak this information to your husband without telling him "I am now seeking information behind your back on the internet".....lol

 

[roughneck]

That’s an ignition or lack of flame detection error.
Check mA from the flame sensor.
You say gas pressure is ok, what is it exactly?
Was the furnace properly converted to LP gas?
What is gas pressure on cold days when it gives issues?